This invention relates to a cam-operated appliance timer. More specifically, a cam-operated appliance timer that employs a nonvarying electrical pulse cooperating with a cam-operated switch to incrementally advance and to delay rotation of a camstack.
Prior art cam-operated timer electronic incremental drive systems employ electronic circuits that are responsive to the camstack by using a program input or feedback from the camstack and provide an electronic pulse of variable duration. Such electronic incremental drive systems employ a sensor means for determining camstack position and provide information on camstack position to an electronic pulsing circuit. The electronic pulsing circuit can then generate a pulse of the proper duration to power the camstack drive motor.
An electronic feedback motor control circuit is complex and costly to manufacture. Additionally, electronic feedback motor control circuits have been unreliable because if there is an error in determining camstack position the timer's performance can be degraded or may cause the timer to malfunction.
A less complex and less expensive alternative to the electronic feedback motor control circuit would decrease production costs and increase the reliability of the cam-operated timer, yet provide the advantages of an electronic incremental drive such as increased accuracy due to the precision of electronically timed pulses, rapid camstack advance using a single motor, and a delay feature.